I'm playing a bit with Entlib. now. Let's say I'm using it a lot actually :). Speaking of Data Access Block in Enterprise Library I'm coming to conclusion that it is not productive to use AddInParameter construction in Database object because:

It does not support parameter size causing ADO.NET pass the max allowed for the specified type.

There is no support for parameter InOut direction (aka AddInOutParameter ?) which I find very useful lately.

I'm going to use AddParameter instead of AddInParameter, despite that it is a bit less readable. Like so: